A person with direct knowledge of the plan said the agreement between the Justice Department and the city will be signed and filed in federal court and Holder will speak in New Orleans. The person spoke on condition of anonymity because the agreement had not yet been made public.

The reforms that Holder will announce are expected to be some of the broadest and strictest ever imposed on a police department. They will be overseen by a federal judge.

The department has been plagued by decades of corruption and mismanagement. It came under renewed scrutiny after Hurricane Katrina struck in 2005.